I was out and about this evening on a parts run. When I came out. There was a family looking T so I showed them the car, let the kids get in and have their photo taken. I was showing them how to hand start the T. It was running for a short time and stalled???? Well I forgot to turn on the fuel valve, Opps. When I went to restart her the starter just spun and did absolutely nothing!

Well in the parking lot, I tore into the bendix. What do I find, but a broken bendix spring. I removed the guts and closed her up. I have never been so happy to have a hand crank.

Now I just have to order a spring tomorrow.

While your at it order a spare spring and bolts and put them in your tool box You wont regret it

And be sure to retard the spark before you engage the starter bendix. Too-advanced spark is the primary reason for broken springs.

Be sure to get the new bolts or cap screws that hold the spring in place and the tab washers too. Don't forget gaskets.

Be sure to remove the burrs on the spiral that may keep the parts from making full travel. That can sometimes brake a spring.

Jason
Let me elaborate on Frank's comments.
Be sure to get the correct type spring and drive head screws with the thin head and the thin locking washers.


Some Model T parts suppliers are still selling thick head screw and locking washers which interfere with the Bendix drive cover pushing it off the hogshead.
I agree with Frank about checking the threads, but that won't break springs, it locks the Bendix drive gear on the end of the shaft and it will not engage.
Ron the Coilman

Jason,

I have springs, locks, and bolts in stock. I am near St Cloud.

After changing my 26 Coupe to 12V I broke 3 bendix springs in a course of 3 or 4 years. An old timer to the hobby suggested I mount a bendix spring inline with the battery lead that goes to the starter. (Like a droping resistor) Haven't broken a spring since and that was 10 years ago. I know there are those that say It ain't so and maybe so. I just know what has been my experience.

I have been good about retarding the spark when starting. However, you never know the how the previous starter owner treated it. This T did not have a starter until the engine was rebuilt. I did not think of ordering gaskets. The lock washers that were on there, where the standard split lock washers not like the ones above (I did order new ones).

She has only been awake for a little more than a week this year. She has been really good starter this spring, with a lot of free starts. Last year the starter could only spin the engine about ½ to 2 rotations before stalling out. I fixed that by replacing a bad grounding strap. I just wonder if that had something to do with the spring breaking. Just a thought.

Ron, thanks for the pictures, I may just use them to help put it all back together.

Jerry
The one additional connection and longer and smaller cross section of the spring compared to the original 1/0 cable adds resistance dropping the voltage to the starting motor. Any drop in voltage will proportionally reduce the torque and speed of the starting motor.
Years ago Chuck Brandt and I conducted tests to understand the characteristics of the original and modified Model T starter on 6 and 12 volts. Here is a plot of the results.

Ron the Coilman